1. Field of the Invention
The present invention relates to an ultrasonic surgical instrument capable of incising, ablating, or coagulating organic tissues by utilizing ultrasonic waves.
2. Description of the Related Art
As an ultrasonic surgical instrument for incising, ablating, or coagulating organic tissues by utilizing ultrasonic waves, in general, there is an apparatus that is described in Jpn. Pat. Appln. KOKAI Publications Nos. 9-98979, 10-5236, etc. This ultrasonic surgical instrument comprises an elongated insertion section that can be inserted into a patient's body. A sheath portion of the insertion section is provided with a mantle tube. A control section on the hand side is coupled to the proximal end portion of the insertion section. The control section is furnished with an ultrasonic vibrator for generating ultrasonic vibration. An operating section for treating organic tissues is provided on the distal end portion of the insertion section. The operating section is provided with an ultrasonic probe.
A substantially shaft-shaped vibration transmitting member is passed through the mantle tube. The proximal end portion of the vibration transmitting member is detachably connected to the ultrasonic vibrator by means of a screw-type junction. Ultrasonic vibration generated by the vibrator is transmitted to the ultrasonic probe of the operating section by means of the vibration transmitting member.
Further, the operating section is provided with a jaw that faces the ultrasonic probe. The jaw is rockably supported on the distal end portion of the insert section. A holding member portion of the jaw that touches an organic tissue is formed of a resin material such as polytetrafluoroethylene.
A control rod for driving the jaw is fitted in the mantle tube for axial movement. The distal end portion of the rod is coupled to the jaw of the operating section. The operating section is provided with a control handle. This handle is coupled to the proximal end portion of the rod.
As the control handle is operated, the control rod is advanced or retreated in the axial direction. As the rod is moved in this manner, the jaw is opened or closed with respect to the ultrasonic probe. If the jaw is closed, the organic tissue is held between the probe and the jaw. Then, the ultrasonic vibrator is driven in this state. As this is done, ultrasonic vibration from the vibrator is transmitted to the ultrasonic probe by means of the vibration transmitting member. Thus, the organic tissue between the probe and the jaw can be incised, ablated, or coagulated by utilizing ultrasonic waves.
Recently, there has been a demand for the proper use of an appropriate ultrasonic surgical instrument according to the region to be treated and the method of treatment. In this case, the distal end portion of the ultrasonic surgical instrument is expected to have an optimum shape for the region to be treated and the method of treatment. To meet this requirement, a set of ultrasonic surgical instruments of a plurality of types having different tip shapes is completed in advance, and the surgical instruments are used alternatively and properly according to the region to be treated and the method of treatment.
In many surgical instruments for endoscopic surgical operations, parts other than the distal end portion are common to a plurality of types of instruments. A reusable ultrasonic surgical instrument, in particular, can be disassembled into a plurality of units to facilitate cleaning. For example, it can be disassembled into three units, including a sheath unit that has a sheath or a mantle tube of an insertion section and a handle of a control section joined together, a vibrator unit having a vibrator, and a probe unit having a probe.
In order to use an ultrasonic surgical instrument having an optimum shape according to the region to be treated and the method of treatment during an endoscopic surgical operation, the probe unit or sheath unit to be joined to the body of the surgical instrument currently in use must be replaced with a new one when the region or method is changed. In replacing the probe unit, in this case, the probe unit and the sheath unit for proper use must be selected and reassembled after the instrument body is disassembled.
In many surgical instruments for endoscopic surgical operations, however, the insertion section is formed having a small outside diameter to ensure low invasion. Correspondingly, the distal end portion of the insertion section is thin and small. Therefore, it is hard apparently to discriminate the difference in the tip shape. In reassembling the disassembled body of the ultrasonic surgical instrument, therefore, the probe unit and the sheath unit cannot be selected and combined properly. Thus, there is a possibility of the probe unit and the sheath unit being assembled in a wrong combination. Although this mistake should be noticed during operation, in this case, the probe unit and the sheath unit must be joined in a proper combination. Thus, reassembling the ultrasonic surgical instrument body requires extra operating time and results in impeding the surgical operation. If the units are used in a wrong combination, moreover, they cannot fulfill their desired function.